ZHCSYB9A October   2003  – May 2025 SN74CB3T3257

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Switching Characteristics 85C
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Performance Plots
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1.      Related Documentation
      2. 9.1.1 接收文档更新通知
      3. 9.1.2 支持资源
      4. 9.1.3 静电放电警告
      5. 9.1.4 术语表
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.1 Overview

The SN74CB3T3257 is a high-speed TTL-compatible FET multiplexer/demultiplexer with low ON-state resistance (ron), allowing for minimal propagation delay. The device fully supports mixed-mode signal operation on all data I/O ports by providing voltage translation that tracks VCC. The SN74CB3T3257 supports systems using 5V TTL, 3.3V LVTTL, and 2.5V CMOS switching standards, as well as user-defined switching levels (see 典型直流电压转换特性).

The SN74CB3T3257 is a 4-bit 1-of-2 multiplexer/demultiplexer with a single output-enable ( OE) input. The select (S) input controls the data path of the multiplexer/demultiplexer. When OE is low, the multiplexer/demultiplexer is enabled, and the A port is connected to the B port, allowing bidirectional data flow between ports. When OE is high, the multiplexer/demultiplexer is disabled, and a high-impedance state exists between the A and B ports.

This device is fully specified for partial-power-down applications using Ioff. The Ioff feature verifies that damaging current does not backflow through the device when the device is powered down. The device has isolation during power off.

To confirm the high-impedance state during power up or power down, tie OE to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.